RFID (Radio frequency IDentification) is a general term for a technology of processing information of items by using a compact semiconductor chip. More specifically, the RFID technology enables a non-contact recognition system which wirelessly transmits information of a product and peripheral information of the product using a compact chip, which is attached to a variety of products. The system that has appeared since 1980 is called a radio recognition system, a radio wave identification system or a radio identification system. The RFID system basically include an RFID tag for storing data, and an RFID reader capable of reading out data stored in the RFID tag.
An RFID tag consists of a semiconductor transponder chip and an antenna, and is categorized into a passive type and an active type. While a passive RFID tag operates by energies provided from a frequency signal of a reader without an internal power source, an active RFID tag has a built-in RF tag battery for self-operation. An RFID tag may be categorized into a silicon-semiconductor chip tag and a non-chip tag which is formed of only an LC element and a plastic or polymer element.
The RFID technology does not need to directly contact or scan an item within a visible band of a reader like in a barcode technology. Having such advantages, the RFID technology is considered as a replacement for a barcode technology, and an application range of the technology is expected to expand continuously. A low-frequency (30 kHz-500 kHz) RFID system is used for transmission in a short distance of less than 1.8 m, and a high-frequency (850 MHz-950 MHz or 2.4 GHz-2.5 GHz) RFID system is used for transmission in a long distance of more than 27 m.
Therefore, the RFID system may be optionally used depending on whether the recognition distance is long or short and depending on radio frequency signals corresponding to application range.
The RFID (Radio Frequency IDentification) system, which includes an RFID reader having reading and decoding functions, an RFID tag including unique information, operation software, and a network, processes information by identifying a thin flat tag fixed to an item. The RFID reader modulates a radio frequency signal having a specific carrier frequency and transmits the signal.
In a case a product attached with the RFID tag is positioned at a read zone of the RFID reader, the RFID tag receives a signal transmitted by the RFID reader, responds to the received signal, and transmits to the RFID reader a predetermined information stored in the built-in memory.